الفهرس 
Review of literatureOnly 14 pages are availabe for public view
 |  | from | 256 |  |  |
| | | from | 256 | | |
Abstract
Production of novel marine bacterial exopolysaccharides: their effect on immunological response and apoptotic pathways for hepatocellular carcinoma Exopolysaccharides (EPSs) are carbohydrate polymers that showed anticancer activity in diverse cancers and gained attention as new source for cancer treatment as recent treatments cause side effects and multidrug resistance. EPSs containing sulfur and uronic acids exhibited antioxidant activity, by restoring cell redox regulation, thus inhibiting cell proliferation and cancer formation. Following this context, our study was performed to: 1) Assess the cytotoxic activity of exopolysaccharides produced by novel Egyptian marine bacterial strains on Hepatocellular carcinoma HepG2 cells. 2) Assess their possible pro-apoptotic effect on apoptotic pathways, in addition to toll like receptors (TLRs).Bacteria were isolated, purified and cultured through routine microbiological techniques. 16SrRNA gene amplification and sequence analyses, Fourier Transform Infra-red (FTIR), Identification of mono-sugars by HPLC molecular weight estimation, sulfur content determination and neutral red uptake assay were utilized. The expression levels of some apoptotic related genes (BCL-2, FasL, P53, tumor necrosis factor (TNF-alpha), Tumour necrosis factor-related apoptosis-inducing ligand (TRAIL), besides the expression of Toll like receptors (TLR2 and TLR9) were screened through the quantitative reverse transcription polymerase chain reaction (qRT-PCR). The expression of 43 apoptotic proteins were assessed using Human Apoptosis Antibody Array-Membrane (43 targets) ab134001 Kit (abcam® England).BLAST showed that the isolates were related to the Bacillus sp. FTIR analysis indicated that the four EPSs under study contained sulfur as substituent functional group but with different percentage in each EPS. The highest sulfur percentage (46%) appeared in the EPS-6 that was produced by Bacillus megaterium isolated from the Mediterranean Sea. HPLC showed that EPSs contained uronic acids which appeared as glucuronic and galacturonic acid in the low molecular weight EPS-6 (4.296×104g mol-1). Arabinose appeared besides the glucuronic and galacturonic acid residues. EPS-6 showed the lowest IC50value (218 µg ml -1) which could be correlated to the presence of sulfure and uronic acids in its structure. According to qRT-PCR expression levels and the antibodies arrays data, all EPSs induce apoptosis through different mediated genes. The most promising EPSs that showed exact apoptotic action towards most of the screened genes were EPS-6 and EPS-RS.